Improvement in manufacture of cast chilled wheels



UNITED STATES GEORGE WHITNEY, OF PHILADELPHIA, PENNSYLVANIA.

IMPRGVEMENT IN MANUFACTURE OF CAST CHILLED WHEELS.

Specification forming part of Letters Patent No. 129,382, dated July 16,1872.

To all whom it may concern:

Be it known that I, GEORGE WHITNEY, of the city and county ofPhiladelphia, in the State of Pennsylvania, have invented a certain newand useful Improvement in the Art of Manufacturing Cast Chilled Wheelsfor railroad uses and for other uses of similar character. The followingis a specification of my said invention:

Heretofore the best cast chilled wheels forrailroads have been made ofcharcoal pig-iron, or, more recently, of pig-iron and steel meltedtogether; but I have discovered, and my invention is based upon thediscovery, (which I have verified by a series of experiments,) thatwrought-iron charged in with pig-iron, or with pig-iron and steel, inany required proportion-say not exceeding fifty per cent. of the wholecharge-can be melted in an ordinary cupola or air-furnace without anyflux, but in the same simple and well-known way as if the chargeconsisted of pig-iron alone; and moreover, that the melted metalproduced from this mixture possesses chilling property. Upon thesefacts, thus ascertained, I have proceeded with my experiments, theresult of which is the invention that forms the subject of this patentand which consists in casting in the ordinary manner, and in molds suchas are ordinarily used for the purpose, chilled wheels for railroads andother similar uses from a charge of wrought-iron, or of wroughtiron,pig-iron, and steel, (the pig-iron constitutin g more than fifty percent. of the charge,) melted together in an ordinary cupola orairfurnace, whereby I am enabled to produce castchilled wheels superiorboth in chill and in strength to wheels made of pig-iron alone, or ofpig-iron and steel melted together, with the advantages of economicalapparatus, moderate requirements of skill in the art, and an enlargedrange of the kinds of pig-iron thus rendered available in thismanufacture. I am unable to designate by any specific name the productof the mixture above described.

As I have found that the product obtained from a charge of equal partsof pig-iron and wrought-iron is a hard and brittle white metal totallyunfit for good strong cast chilled wheels, (aside from the fact thatsuch product is obtained only with a very large percentage of loss onsuch a charge,) and that this metal has,

moreover, when cast on a chill, an absolute and uncontrollable tendencyto chill throughout or at least to such an extent as would be highlydetrimental to the strength and toughness so essential in the hub andplate of a cast car-wheel, I do not propose to use as much wrought-ironas pig-iron, nor as much Wroughtiron and steel together as pig-iron; andI do not claim herein the manufacture of cast chilled wheels, exceptwhen made from the product of wrought-iron and pig-iron, or ofwroughtiron and steel and pig-iron melted together, the pig-ironpreponderating positively in the charge.

I have, in practice, varied the relative proportions of the metalsspecified, and have attained what I deem the bests results from chargesrespectively made up as follows: Charcoal pig-iron, forty per cent;anthracite pigiron, forty per cent. 5 wrought-iron, twenty per cent; or,anthracite pig-iron, eighty per cent; wroughtiron, twenty per cent; or,charcoal pig-iron, forty per cent; anthracite pig-iron, forty per cent;Bessemer steel, ten per cent;

wrought-iron, ten per cent. .or, anthracite pig- I iron, 80 per cent.Bessemer steel, ten per cent.; wrought-iron, ten per cent.

It should be observed that I have used charcoal pig-irons with goodchilling property and anthracite pig-irons having slighter tendencies tochill, and I have attained good results with the mixtures abovespecified but with different pig-irons different proportions ofwroughtiron or of wrought-iron and steel maybe used conformable to thedifferent qualities of the pig-irons as to chilling property andstrength, but the pig-iron always preponderating positively in thecharge, so as to produce the requisite chill and strength in the wheel,as is fully understood by those skilled in the art of making castchilled wheels.

' In my practice I have used for my wroughtiron old railroad rails outinto lengths about the same as the pieces into which the pig-iron isusually broken up for charging into the ordinary cupola-furnace. Thewheels should be removed from the molds as soon as practicable afterbeing cast and slow cooled in any of the ordinary modes now practicedwith castchilled railroad wheels. I prefer the method of slow coolingdescribed in the Letters Patent granted to Asa Whitney, April 25, 1848.

So long as the pig-iron constitutes positively As a new article ofmanufacture, a cast more than fifty per cent. of the charge I do notchilled car-Wheel, made from the product of confine myself to any exactor fixed percentwrought-iron and pig-iron, or of Wrought-iron, age ofwrought-iron or of Wroughtiron and pig-iron, and steel, melted together,the pig- 'steel, as these must necessarily be varied someironpreponderating in the charge, substanwhat in View of the requirements Ihave stated, tially as hereinbefore set forth.

and which are well understood by those skilled GEO. WHITNEY. in thisart; but Witnesses:

What I claim as my invention, and desire GEO. H. KIRK,

to secure by Letters Patent, is R0131. S. REDFIELD.

